/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.messaging.tcp.reactor;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelPipeline;
import reactor.core.publisher.DirectProcessor;
import reactor.core.publisher.Mono;
import reactor.ipc.netty.NettyInbound;
import reactor.ipc.netty.NettyOutbound;
import reactor.ipc.netty.NettyPipeline;

import org.springframework.messaging.Message;
import org.springframework.messaging.tcp.TcpConnection;
import org.springframework.util.concurrent.ListenableFuture;

/**
 * Reactor Netty based implementation of {@link TcpConnection}.
 *
 * @author Rossen Stoyanchev
 * @since 5.0
 */
public class ReactorNettyTcpConnection<P> implements TcpConnection<P> {

    private final NettyInbound inbound;

    private final NettyOutbound outbound;

    private final ReactorNettyCodec<P> codec;

    private final DirectProcessor<Void> closeProcessor;


    public ReactorNettyTcpConnection(NettyInbound inbound, NettyOutbound outbound,
                                     ReactorNettyCodec<P> codec, DirectProcessor<Void> closeProcessor) {

        this.inbound = inbound;
        this.outbound = outbound;
        this.codec = codec;
        this.closeProcessor = closeProcessor;
    }


    @Override
    public ListenableFuture<Void> send(Message<P> message) {
        ByteBuf byteBuf = this.outbound.alloc().buffer();
        this.codec.encode(message, byteBuf);
        Mono<Void> sendCompletion = this.outbound.send(Mono.just(byteBuf)).then();
        return new MonoToListenableFutureAdapter<>(sendCompletion);
    }

    @Override
    @SuppressWarnings("deprecation")
    public void onReadInactivity(Runnable runnable, long inactivityDuration) {
        // TODO: workaround for https://github.com/reactor/reactor-netty/issues/22
        ChannelPipeline pipeline = this.inbound.context().channel().pipeline();
        String name = NettyPipeline.OnChannelReadIdle;
        if (pipeline.context(name) != null) {
            pipeline.remove(name);
        }

        this.inbound.onReadIdle(inactivityDuration, runnable);
    }

    @Override
    @SuppressWarnings("deprecation")
    public void onWriteInactivity(Runnable runnable, long inactivityDuration) {
        this.outbound.onWriteIdle(inactivityDuration, runnable);
    }

    @Override
    public void close() {
        this.closeProcessor.onComplete();
    }

}
